Decorative shell



FIG. 1 is an isometric view of the decorative shell;

FIG. 2 is a front elevational view of the decorative shell as depicted in FIG. 1;

FIG. 3 is an elevational view of a first side of the decorative shell as depicted in FIG. 1 taken generally along the view lines 3—3 of FIG. 6;

FIG. 4 is a back elevational view of the decorative shell as depicted in FIG. 1;

FIG. 5 is an elevational view of a second side of the decorative shell as depicted in FIG. 1; and,

FIG. 6 is a plan view of the decorative shell as depicted in FIG. 1.

Also, structures shown in broken lines form no part of the claimed design. 

The ornamental design for a decorative shell, as shown and described. 